Native BSD host USB support (Juergen Lock, Lonnie Mendez)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5780 c046a42c-6fe2-441c-8c8c-71466251a162

5 files changed, 673 insertions, 24 deletions

diff --git a/Makefile b/Makefile
index 3ed8b2ac46..bbd54fc079 100644
--- a/Makefile
+++ b/Makefile
@@ -74,7 +74,7 @@ OBJS+=ssd0303.o ssd0323.o ads7846.o stellaris_input.o twl92230.o
 OBJS+=tmp105.o lm832x.o
 OBJS+=scsi-disk.o cdrom.o
 OBJS+=scsi-generic.o
-OBJS+=usb.o usb-hub.o usb-linux.o usb-hid.o usb-msd.o usb-wacom.o
+OBJS+=usb.o usb-hub.o usb-$(HOST_USB).o usb-hid.o usb-msd.o usb-wacom.o
 OBJS+=usb-serial.o usb-net.o
 OBJS+=sd.o ssi-sd.o
 OBJS+=bt.o bt-host.o bt-vhci.o bt-l2cap.o bt-sdp.o bt-hci.o bt-hid.o usb-bt.o
diff --git a/configure b/configure
index b1daf440b4..ac458dce42 100755
--- a/configure
+++ b/configure
@@ -221,6 +221,7 @@ audio_drv_list="oss"
 audio_possible_drivers="oss alsa sdl esd pa"
 linux="yes"
 linux_user="yes"
+usb="linux"
 if [ "$cpu" = "i386" -o "$cpu" = "x86_64" ] ; then
     kqemu="yes"
     audio_possible_drivers="$audio_possible_drivers fmod"
@@ -231,6 +232,7 @@ esac
 if [ "$bsd" = "yes" ] ; then
   if [ "$darwin" != "yes" ] ; then
     make="gmake"
+    usb="bsd"
   fi
   bsd_user="yes"
 fi
@@ -1365,6 +1367,19 @@ fi
 
 echo "#define CONFIG_UNAME_RELEASE \"$uname_release\"" >> $config_h
 
+# USB host support
+case "$usb" in
+linux)
+  echo "HOST_USB=linux" >> $config_mak
+;;
+bsd)
+  echo "HOST_USB=bsd" >> $config_mak
+;;
+*)
+  echo "HOST_USB=stub" >> $config_mak
+;;
+esac
+
 tools=
 if test `expr "$target_list" : ".*softmmu.*"` != 0 ; then
   tools="qemu-img\$(EXESUF) $tools"
diff --git a/usb-bsd.c b/usb-bsd.c
new file mode 100644
index 0000000000..567aa81d81
--- /dev/null
+++ b/usb-bsd.c
@@ -0,0 +1,608 @@
+/*
+ * BSD host USB redirector
+ *
+ * Copyright (c) 2006 Lonnie Mendez
+ * Portions of code and concepts borrowed from
+ * usb-linux.c and libusb's bsd.c and are copyright their respective owners.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu-common.h"
+#include "console.h"
+#include "hw/usb.h"
+
+/* usb.h declares these */
+#undef USB_SPEED_HIGH
+#undef USB_SPEED_FULL
+#undef USB_SPEED_LOW
+
+#include <sys/ioctl.h>
+#include <dev/usb/usb.h>
+#include <signal.h>
+
+/* This value has maximum potential at 16.
+ * You should also set hw.usb.debug to gain
+ * more detailed view.
+ */
+//#define DEBUG
+#define UGEN_DEBUG_LEVEL 0
+
+
+typedef int USBScanFunc(void *opaque, int bus_num, int addr, int class_id,
+                        int vendor_id, int product_id,
+                        const char *product_name, int speed);
+static int usb_host_find_device(int *pbus_num, int *paddr,
+                                const char *devname);
+
+typedef struct USBHostDevice {
+    USBDevice dev;
+    int ep_fd[USB_MAX_ENDPOINTS];
+    int devfd;
+    char devpath[32];
+} USBHostDevice;
+
+
+static int ensure_ep_open(USBHostDevice *dev, int ep, int mode)
+{
+    char buf[32];
+    int fd;
+
+    /* Get the address for this endpoint */
+    ep = UE_GET_ADDR(ep);
+
+    if (dev->ep_fd[ep] < 0) {
+#if __FreeBSD__
+        snprintf(buf, sizeof(buf) - 1, "%s.%d", dev->devpath, ep);
+#else
+        snprintf(buf, sizeof(buf) - 1, "%s.%02d", dev->devpath, ep);
+#endif
+        /* Try to open it O_RDWR first for those devices which have in and out
+         * endpoints with the same address (eg 0x02 and 0x82)
+         */
+        fd = open(buf, O_RDWR);
+        if (fd < 0 && errno == ENXIO)
+            fd = open(buf, mode);
+        if (fd < 0) {
+#ifdef DEBUG
+            printf("ensure_ep_open: failed to open device endpoint %s: %s\n",
+                   buf, strerror(errno));
+#endif
+        }
+        dev->ep_fd[ep] = fd;
+    }
+
+    return dev->ep_fd[ep];
+}
+
+static void ensure_eps_closed(USBHostDevice *dev)
+{
+    int epnum = 1;
+
+    if (!dev)
+        return;
+
+    while (epnum < USB_MAX_ENDPOINTS) {
+        if (dev->ep_fd[epnum] >= 0) {
+            close(dev->ep_fd[epnum]);
+            dev->ep_fd[epnum] = -1;
+        }
+        epnum++;
+    }
+}
+
+static void usb_host_handle_reset(USBDevice *dev)
+{
+#if 0
+    USBHostDevice *s = (USBHostDevice *)dev;
+#endif
+}
+
+/* XXX:
+ * -check device states against transfer requests
+ *  and return appropriate response
+ */
+static int usb_host_handle_control(USBDevice *dev,
+                                   int request,
+                                   int value,
+                                   int index,
+                                   int length,
+                                   uint8_t *data)
+{
+    USBHostDevice *s = (USBHostDevice *)dev;
+    struct usb_ctl_request req;
+    struct usb_alt_interface aiface;
+    int ret, timeout = 50;
+
+    if ((request >> 8) == UT_WRITE_DEVICE &&
+        (request & 0xff) == UR_SET_ADDRESS) {
+
+        /* specific SET_ADDRESS support */
+        dev->addr = value;
+        return 0;
+    } else if ((request >> 8) == UT_WRITE_DEVICE &&
+               (request & 0xff) == UR_SET_CONFIG) {
+
+        ensure_eps_closed(s); /* can't do this without all eps closed */
+
+        ret = ioctl(s->devfd, USB_SET_CONFIG, &value);
+        if (ret < 0) {
+#ifdef DEBUG
+            printf("handle_control: failed to set configuration - %s\n",
+                   strerror(errno));
+#endif
+            return USB_RET_STALL;
+        }
+
+        return 0;
+    } else if ((request >> 8) == UT_WRITE_INTERFACE &&
+               (request & 0xff) == UR_SET_INTERFACE) {
+
+        aiface.uai_interface_index = index;
+        aiface.uai_alt_no = value;
+
+        ensure_eps_closed(s); /* can't do this without all eps closed */
+        ret = ioctl(s->devfd, USB_SET_ALTINTERFACE, &aiface);
+        if (ret < 0) {
+#ifdef DEBUG
+            printf("handle_control: failed to set alternate interface - %s\n",
+                   strerror(errno));
+#endif
+            return USB_RET_STALL;
+        }
+
+        return 0;
+    } else {
+        req.ucr_request.bmRequestType = request >> 8;
+        req.ucr_request.bRequest = request & 0xff;
+        USETW(req.ucr_request.wValue, value);
+        USETW(req.ucr_request.wIndex, index);
+        USETW(req.ucr_request.wLength, length);
+        req.ucr_data = data;
+        req.ucr_flags = USBD_SHORT_XFER_OK;
+
+        ret = ioctl(s->devfd, USB_SET_TIMEOUT, &timeout);
+#if (__NetBSD__ || __OpenBSD__)
+        if (ret < 0 && errno != EINVAL) {
+#else
+        if (ret < 0) {
+#endif
+#ifdef DEBUG
+            printf("handle_control: setting timeout failed - %s\n",
+                   strerror(errno));
+#endif
+        }
+
+        ret = ioctl(s->devfd, USB_DO_REQUEST, &req);
+        /* ugen returns EIO for usbd_do_request_ no matter what
+         * happens with the transfer */
+        if (ret < 0) {
+#ifdef DEBUG
+            printf("handle_control: error after request - %s\n",
+                   strerror(errno));
+#endif
+            return USB_RET_NAK; // STALL
+        } else {
+            return req.ucr_actlen;
+        }
+    }
+}
+
+static int usb_host_handle_data(USBDevice *dev, USBPacket *p)
+{
+    USBHostDevice *s = (USBHostDevice *)dev;
+    int ret, fd, mode;
+    int one = 1, shortpacket = 0, timeout = 50;
+    sigset_t new_mask, old_mask;
+    uint8_t devep = p->devep;
+
+    /* protect data transfers from SIGALRM signal */
+    sigemptyset(&new_mask);
+    sigaddset(&new_mask, SIGALRM);
+    sigprocmask(SIG_BLOCK, &new_mask, &old_mask);
+
+    if (p->pid == USB_TOKEN_IN) {
+        devep |= 0x80;
+        mode = O_RDONLY;
+        shortpacket = 1;
+    } else {
+        mode = O_WRONLY;
+    }
+
+    fd = ensure_ep_open(s, devep, mode);
+    if (fd < 0) {
+        sigprocmask(SIG_SETMASK, &old_mask, NULL);
+        return USB_RET_NODEV;
+    }
+
+    if (ioctl(fd, USB_SET_TIMEOUT, &timeout) < 0) {
+#ifdef DEBUG
+        printf("handle_data: failed to set timeout - %s\n",
+               strerror(errno));
+#endif
+    }
+
+    if (shortpacket) {
+        if (ioctl(fd, USB_SET_SHORT_XFER, &one) < 0) {
+#ifdef DEBUG
+            printf("handle_data: failed to set short xfer mode - %s\n",
+                   strerror(errno));
+#endif
+            sigprocmask(SIG_SETMASK, &old_mask, NULL);
+        }
+    }
+
+    if (p->pid == USB_TOKEN_IN)
+        ret = read(fd, p->data, p->len);
+    else
+        ret = write(fd, p->data, p->len);
+
+    sigprocmask(SIG_SETMASK, &old_mask, NULL);
+
+    if (ret < 0) {
+#ifdef DEBUG
+        printf("handle_data: error after %s data - %s\n",
+               pid == USB_TOKEN_IN ? "reading" : "writing", strerror(errno));
+#endif
+        switch(errno) {
+        case ETIMEDOUT:
+        case EINTR:
+            return USB_RET_NAK;
+        default:
+            return USB_RET_STALL;
+        }
+    } else {
+        return ret;
+    }
+}
+
+static void usb_host_handle_destroy(USBDevice *opaque)
+{
+    USBHostDevice *s = (USBHostDevice *)opaque;
+    int i;
+
+    for (i = 0; i < USB_MAX_ENDPOINTS; i++)
+        if (s->ep_fd[i] >= 0)
+            close(s->ep_fd[i]);
+
+    if (s->devfd < 0)
+        return;
+
+    close(s->devfd);
+
+    qemu_free(s);
+}
+
+USBDevice *usb_host_device_open(const char *devname)
+{
+    struct usb_device_info bus_info, dev_info;
+    USBHostDevice *dev;
+    char ctlpath[PATH_MAX + 1];
+    char buspath[PATH_MAX + 1];
+    int bfd, dfd, bus, address, i;
+    int ugendebug = UGEN_DEBUG_LEVEL;
+
+    if (usb_host_find_device(&bus, &address, devname) < 0)
+        return NULL;
+
+    snprintf(buspath, PATH_MAX, "/dev/usb%d", bus);
+
+    bfd = open(buspath, O_RDWR);
+    if (bfd < 0) {
+#ifdef DEBUG
+        printf("usb_host_device_open: failed to open usb bus - %s\n",
+               strerror(errno));
+#endif
+        return NULL;
+    }
+
+    bus_info.udi_addr = address;
+    if (ioctl(bfd, USB_DEVICEINFO, &bus_info) < 0) {
+#ifdef DEBUG
+        printf("usb_host_device_open: failed to grab bus information - %s\n",
+               strerror(errno));
+#endif
+        return NULL;
+    }
+
+#if __FreeBSD__
+    snprintf(ctlpath, PATH_MAX, "/dev/%s", bus_info.udi_devnames[0]);
+#else
+    snprintf(ctlpath, PATH_MAX, "/dev/%s.00", bus_info.udi_devnames[0]);
+#endif
+
+    dfd  = open(ctlpath, O_RDWR);
+    if (dfd < 0) {
+        dfd = open(ctlpath, O_RDONLY);
+        if (dfd < 0) {
+#ifdef DEBUG
+            printf("usb_host_device_open: failed to open usb device %s - %s\n",
+                   ctlpath, strerror(errno));
+#endif
+        }
+    }
+
+    if (dfd >= 0) {
+        dev = qemu_mallocz(sizeof(USBHostDevice));
+        if (!dev)
+            goto fail;
+        dev->devfd = dfd;
+
+        if (ioctl(dfd, USB_GET_DEVICEINFO, &dev_info) < 0) {
+#ifdef DEBUG
+            printf("usb_host_device_open: failed to grab device info - %s\n",
+                   strerror(errno));
+#endif
+            goto fail;
+        }
+
+        if (dev_info.udi_speed == 1)
+            dev->dev.speed = USB_SPEED_LOW - 1;
+        else
+            dev->dev.speed = USB_SPEED_FULL - 1;
+
+        dev->dev.handle_packet = usb_generic_handle_packet;
+
+        dev->dev.handle_reset = usb_host_handle_reset;
+        dev->dev.handle_control = usb_host_handle_control;
+        dev->dev.handle_data = usb_host_handle_data;
+        dev->dev.handle_destroy = usb_host_handle_destroy;
+
+        if (strncmp(dev_info.udi_product, "product", 7) != 0)
+            pstrcpy(dev->dev.devname, sizeof(dev->dev.devname),
+                    dev_info.udi_product);
+        else
+            snprintf(dev->dev.devname, sizeof(dev->dev.devname),
+                     "host:%s", devname);
+
+        pstrcpy(dev->devpath, sizeof(dev->devpath), "/dev/");
+	strcat(dev->devpath, dev_info.udi_devnames[0]);
+
+        /* Mark the endpoints as not yet open */
+        for (i = 0; i < USB_MAX_ENDPOINTS; i++)
+           dev->ep_fd[i] = -1;
+
+        ioctl(dfd, USB_SETDEBUG, &ugendebug);
+
+        return (USBDevice *)dev;
+    }
+
+fail:
+    return NULL;
+}
+
+static int usb_host_scan(void *opaque, USBScanFunc *func)
+{
+    struct usb_device_info bus_info;
+    struct usb_device_info dev_info;
+    uint16_t vendor_id, product_id, class_id, speed;
+    int bfd, dfd, bus, address;
+    char busbuf[20], devbuf[20], product_name[256];
+    int ret = 0;
+
+    for (bus = 0; bus < 10; bus++) {
+
+        snprintf(busbuf, sizeof(busbuf) - 1, "/dev/usb%d", bus);
+        bfd = open(busbuf, O_RDWR);
+        if (bfd < 0)
+	    continue;
+
+        for (address = 1; address < 127; address++) {
+
+            bus_info.udi_addr = address;
+            if (ioctl(bfd, USB_DEVICEINFO, &bus_info) < 0)
+                continue;
+
+            /* only list devices that can be used by generic layer */
+            if (strncmp(bus_info.udi_devnames[0], "ugen", 4) != 0)
+                continue;
+
+#if __FreeBSD__
+            snprintf(devbuf, sizeof(devbuf) - 1, "/dev/%s", bus_info.udi_devnames[0]);
+#else
+            snprintf(devbuf, sizeof(devbuf) - 1, "/dev/%s.00", bus_info.udi_devnames[0]);
+#endif
+
+            dfd = open(devbuf, O_RDONLY);
+            if (dfd < 0) {
+#ifdef DEBUG
+                printf("usb_host_scan: couldn't open device %s - %s\n", devbuf,
+                       strerror(errno));
+#endif
+                continue;
+            }
+
+            if (ioctl(dfd, USB_GET_DEVICEINFO, &dev_info) < 0)
+                printf("usb_host_scan: couldn't get device information for %s - %s\n",
+                       devbuf, strerror(errno));
+
+            // XXX: might need to fixup endianess of word values before copying over
+
+            vendor_id = dev_info.udi_vendorNo;
+            product_id = dev_info.udi_productNo;
+            class_id = dev_info.udi_class;
+            speed = dev_info.udi_speed;
+
+            if (strncmp(dev_info.udi_product, "product", 7) != 0)
+                pstrcpy(product_name, sizeof(product_name),
+                        dev_info.udi_product);
+            else
+                product_name[0] = '\0';
+
+            ret = func(opaque, bus, address, class_id, vendor_id,
+                       product_id, product_name, speed);
+
+            close(dfd);
+
+            if (ret)
+                goto the_end;
+        }
+
+        close(bfd);
+    }
+
+the_end:
+    return ret;
+}
+
+typedef struct FindDeviceState {
+    int vendor_id;
+    int product_id;
+    int bus_num;
+    int addr;
+} FindDeviceState;
+
+static int usb_host_find_device_scan(void *opaque, int bus_num, int addr,
+                                     int class_id,
+                                     int vendor_id, int product_id,
+                                     const char *product_name, int speed)
+{
+    FindDeviceState *s = opaque;
+    if (vendor_id == s->vendor_id &&
+        product_id == s->product_id) {
+        s->bus_num = bus_num;
+        s->addr = addr;
+        return 1;
+     } else {
+        return 0;
+     }
+}
+
+
+/* the syntax is :
+   'bus.addr' (decimal numbers) or
+   'vendor_id:product_id' (hexa numbers) */
+static int usb_host_find_device(int *pbus_num, int *paddr,
+                                const char *devname)
+{
+    const char *p;
+    int ret;
+    FindDeviceState fs;
+
+    p = strchr(devname, '.');
+    if (p) {
+        *pbus_num = strtoul(devname, NULL, 0);
+        *paddr = strtoul(p + 1, NULL, 0);
+        return 0;
+    }
+    p = strchr(devname, ':');
+    if (p) {
+        fs.vendor_id = strtoul(devname, NULL, 16);
+        fs.product_id = strtoul(p + 1, NULL, 16);
+        ret = usb_host_scan(&fs, usb_host_find_device_scan);
+        if (ret) {
+            *pbus_num = fs.bus_num;
+            *paddr = fs.addr;
+            return 0;
+        }
+     }
+     return -1;
+}
+
+/**********************/
+/* USB host device info */
+
+struct usb_class_info {
+    int class;
+    const char *class_name;
+};
+
+static const struct usb_class_info usb_class_info[] = {
+    { USB_CLASS_AUDIO, "Audio"},
+    { USB_CLASS_COMM, "Communication"},
+    { USB_CLASS_HID, "HID"},
+    { USB_CLASS_HUB, "Hub" },
+    { USB_CLASS_PHYSICAL, "Physical" },
+    { USB_CLASS_PRINTER, "Printer" },
+    { USB_CLASS_MASS_STORAGE, "Storage" },
+    { USB_CLASS_CDC_DATA, "Data" },
+    { USB_CLASS_APP_SPEC, "Application Specific" },
+    { USB_CLASS_VENDOR_SPEC, "Vendor Specific" },
+    { USB_CLASS_STILL_IMAGE, "Still Image" },
+    { USB_CLASS_CSCID, "Smart Card" },
+    { USB_CLASS_CONTENT_SEC, "Content Security" },
+    { -1, NULL }
+};
+
+static const char *usb_class_str(uint8_t class)
+{
+    const struct usb_class_info *p;
+    for (p = usb_class_info; p->class != -1; p++) {
+        if (p->class == class)
+            break;
+    }
+    return p->class_name;
+}
+
+void usb_info_device(int bus_num, int addr, int class_id,
+                     int vendor_id, int product_id,
+                     const char *product_name,
+                     int speed)
+{
+    const char *class_str, *speed_str;
+
+    switch(speed) {
+    case USB_SPEED_LOW:
+        speed_str = "1.5";
+        break;
+    case USB_SPEED_FULL:
+        speed_str = "12";
+        break;
+    case USB_SPEED_HIGH:
+        speed_str = "480";
+        break;
+    default:
+        speed_str = "?";
+        break;
+    }
+
+    term_printf("  Device %d.%d, speed %s Mb/s\n",
+                bus_num, addr, speed_str);
+    class_str = usb_class_str(class_id);
+    if (class_str)
+        term_printf("    %s:", class_str);
+    else
+        term_printf("    Class %02x:", class_id);
+    term_printf(" USB device %04x:%04x", vendor_id, product_id);
+    if (product_name[0] != '\0')
+        term_printf(", %s", product_name);
+    term_printf("\n");
+}
+
+static int usb_host_info_device(void *opaque, int bus_num, int addr,
+                                int class_id,
+                                int vendor_id, int product_id,
+                                const char *product_name,
+                                int speed)
+{
+    usb_info_device(bus_num, addr, class_id, vendor_id, product_id,
+                    product_name, speed);
+    return 0;
+}
+
+void usb_host_info(void)
+{
+    usb_host_scan(NULL, usb_host_info_device);
+}
+
+/* XXX add this */
+int usb_host_device_close(const char *devname)
+{
+    return 0;
+}
diff --git a/usb-linux.c b/usb-linux.c
index a499c10e94..334b45d30f 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -34,7 +34,6 @@
 #include "qemu-timer.h"
 #include "console.h"
 
-#if defined(__linux__)
 #include <dirent.h>
 #include <sys/ioctl.h>
 #include <signal.h>
@@ -1697,25 +1696,3 @@ void usb_host_info(void)
     	term_printf("    Device %s.%s ID %s:%s\n", bus, addr, vid, pid);
     }
 }
-
-#else
-
-#include "hw/usb.h"
-
-void usb_host_info(void)
-{
-    term_printf("USB host devices not supported\n");
-}
-
-/* XXX: modify configure to compile the right host driver */
-USBDevice *usb_host_device_open(const char *devname)
-{
-    return NULL;
-}
-
-int usb_host_device_close(const char *devname)
-{
-    return 0;
-}
-
-#endif
diff --git a/usb-stub.c b/usb-stub.c
new file mode 100644
index 0000000000..29aee5dad1
--- /dev/null
+++ b/usb-stub.c
@@ -0,0 +1,49 @@
+/*
+ * Stub host USB redirector
+ *
+ * Copyright (c) 2005 Fabrice Bellard
+ *
+ * Copyright (c) 2008 Max Krasnyansky
+ *      Support for host device auto connect & disconnect
+ *      Major rewrite to support fully async operation
+ *
+ * Copyright 2008 TJ <linux@tjworld.net>
+ *      Added flexible support for /dev/bus/usb /sys/bus/usb/devices in addition
+ *      to the legacy /proc/bus/usb USB device discovery and handling
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "hw/usb.h"
+
+void usb_host_info(void)
+{
+    term_printf("USB host devices not supported\n");
+}
+
+/* XXX: modify configure to compile the right host driver */
+USBDevice *usb_host_device_open(const char *devname)
+{
+    return NULL;
+}
+
+int usb_host_device_close(const char *devname)
+{
+    return 0;
+}